A method of manufacturing a semiconductor device includes processes of, e.g., forming a thin film on a target substrate to be processed, etching the formed thin film, surface-treating the thin film and the like. A semiconductor device having a multilayer wiring structure is manufactured through these processes.
In a film forming apparatus employed in, e.g., the process of forming the film on the target substrate among these semiconductor manufacturing processes, the film formation is performed by supplying various gases related to the film formation into a processing chamber having therein the target substrate to be processed.
In the above film forming apparatus, the processing chamber having therein the target substrate is generally made of aluminum or an aluminum alloy. Since the aluminum or the aluminum alloy is light, easily worked, and relatively easily available, it has been widely used for making the processing chamber of the film forming apparatus. For example, in Patent Documents 1 and 2, an apparatus of which a processing chamber is made of aluminum or an aluminum alloy has been proposed. Further, Patent Documents 3 and 4 disclose methods of forming a nonporous anodic oxide film on a surface of aluminum or an aluminum alloy to provide the aluminum or an aluminum alloy of which a corrosion resistance is favorable and an amount of a discharge gas is small.
Patent Document 1: Japanese Patent Laid-open Application No. 2003-7694.
Patent Document 2: Japanese Patent Laid-open Application No. 2001-2623250.
Patent Document 3: Japanese Patent Laid-open Application No. H9-184094.
Patent Document 4: Japanese Patent Laid-open Application No. H9-302499.
However, the processing chamber made of aluminum or an aluminum alloy suffers from a problem in that, when specific gases are supplied to the processing chamber, the aluminum forming the processing chamber is eluted and the eluted aluminum is scattered to be attached to the target substrate to contaminate the target substrate.
For example, when a gas composed of a metal alkoxide is supplied to the processing chamber, there has been a problem in that aluminum is eluted to a great extent, entailing the possibility of the target substrate being contaminated by aluminum or metals contained in an aluminum alloy.